Methods and terminal devices

ABSTRACT

A method and terminal device are provided which effect the steps of receiving a message indicating that a user of another terminal device has pressed a talk button, the message including a geographical location of the other terminal device, or any information derived therefrom; and indicating the geographical location of the other terminal device to a user of the terminal device. A further method and terminal device are provided which effect the steps of: in response to a user of a terminal device pressing a talk button, writing information describing the geographical location of the terminal device, or any information derived therefrom, into a message; and sending the message to another terminal device or to a communications network.

BACKGROUND OF THE INVENTION

Push-to-Talk over Cellular, PoC, is a relatively new service offered insome cellular networks, and has gradually gained more success on themarket. In PoC, one subscriber can transmit speech to another subscriberor a group of subscribers simply by pressing a speak button. Thetransmission is half-duplex only; i.e., only one party can speak at atime.

The communication channel between the parties of the conversation isusually a packet-switched communication channel which is preferablyestablished at the very beginning of the service. As a consequence, aspeech message, having speech coded at the terminal device, usually canbe transferred almost instantaneously without an annoying delay due tothe establishment of the packet switched communication channel betweenthe individual speech messages that are to be transmitted.

A user receiving a Push-to-Talk over Cellular message cannot know thegeographical location of the talking party without asking it from thespeaker, which is time-consuming and, when PoC is used as a groupservice, can be annoying to the others who then hear the reply as well.

SUMMARY OF THE INVENTION

The present invention is therefore directed toward enabling a party of aconversation to obtain location information of another party in aconvenient way.

If the geographical location information is received at a terminal in amessage that indicates that a user of another terminal device haspressed a talk button, it is clearly advantageous that one party of theconversation does not need to ask the other party about his or herwhereabouts. Furthermore, the geographical location information maybecome important for the recipient only at the point when the user ofthe other terminal device is going to say or is saying something, andhas therefore pressed the talk button. In this manner, it can be ensuredthat the user obtains the geographical location when he or she needs itor has any interest in it, not too early or not too late.

Indicating the geographical location can be performed in many ways. Thisis particularly useful if the geographical location is indicated to theuser of the terminal device in relation to his or her own geographicallocation. This helps the party receiving the speech message to sense thedirection where the speech is actually coming from. This may improve theuser's feeling of mutual understanding, or help to locate the other userin a crowded area. Particularly advantageous embodiments for carryingout this feature are: indicating a direction of the terminal device fromthe geographical location of the other terminal device; indicating adistance of the terminal device from the other terminal device;indicating the geographical location of the terminal device on a maptogether with the location of the other terminal device; and indicatingthe coordinates of the terminal device as well as those of the otherterminal device.

If the geographical location information is written into a message thatis transmitted to another terminal device either directly or via anetwork, it is advantageous that one party of the conversation does notneed to tell the other party about his or her whereabouts.

Nevertheless, in order to avoid privacy problems and any conflicts withthe legislator in some countries, it may become necessary to enable usercontrol over the decision whether or not geographical locationinformation may be sent.

Therefore, by setting a parameter controllable by a user of the terminaldevice, sending the geographical location information can be disabled orenabled. In this manner, it is also possible to use, for example, thePoC service without revealing the address.

Furthermore, if the parameter controllable by a user of the terminaldevice shows that the geographical location may be indicated to anotherdevice to which the message, or any message derived therefrom, is goingto be sent, partial anonymity can be guaranteed. In this manner, forexample, parents may ensure that the child's geographical location istransmitted to parents and/or trusted friends only, but not to unknownpeople that might cause harm to the child.

Common to all embodiments of the present invention is that if themessage is a message that would, in any case, be sent to the otherparty, some traffic can be avoided since no dedicated geographicallocation messages need to be transmitted any more.

If the present invention is used in connection with PoC, such messagesare then preferably Push-to-Talk over Cellular messages. Some specialcases of these messages are a REFER message, a Floor taken message, or aTalk burst, since they are sent, in any case, if a speech message istransmitted between two terminal devices.

Additional features and advantages of the present invention aredescribed in, and will be apparent from, the following DetailedDescription of the Invention and the Figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A shows a modern network architecture for enabling a PoC service.

FIG. 1B shows a simplified functional block diagram of a terminaldevice.

FIG. 2 illustrates the implementation of a PoC service.

FIG. 3 shows an exemplary signalling diagram for PoC.

FIGS. 4 and 5 show more detailed signalling diagrams for PoC.

FIG. 5 is another model case for PoC.

FIGS. 6A and 6B illustrate possible structures of the message carryinggeographical location information.

Same reference numerals refer to similar elements throughout 10 theFigures.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1A shows a modern network architecture for enabling the PoCservice. A terminal device 101, sometimes denoted as user equipment,such as a mobile terminal or a portable digital assistant, can be inwireless connection with a communications network 100 or with anotherterminal device.

The communications network 100 may include a GSM/EDGE Radio AccessNetwork 103 which is further connected to a Circuit-Switched CoreNetwork 105 and a Packet-Switched Core Network 107. The latter isfurther connected to an IP-based Multimedia Subsystem IMS 109 whichresembles, more or less, the Internet. The PoC service can be located inthe Internet 111 or in any IP-based network.

FIG. 1B shows a simplified functional block diagram of a terminal device101. The terminal device 101 includes receiving part 151, transmittingpart 153, processing unit 155, memory 161, voice input part 157 andvoice output part 159, visual indication part 163, and push button 167.The processing unit can run application 165 for offering the PoCservice. The receiving part 151 and the transmitting part 153 may enablethe terminal device 101 to be in communication with the communicationsnetwork 100 or with another terminal device.

An example of the voice input part 157 is a microphone, and an exampleof the voice output part 159 a loudspeaker. A skilled person appreciatesthat some fundamental components (e.g., rechargeable battery or anyother energy source, amplifiers, antennas, etc.) have been omitted fromFIG. 1B for clarity. These features are nevertheless rather well knownper se such that omitting them does not make understanding the presentinvention any more difficult.

FIG. 2 illustrates the implementation of the PoC service. ThePacket-Switched Core Network 107A, through which the terminal device 100can have its connections, is connected to the IMS 109A Most messages arerouted via IMS core 203A. The PoC server 201 can be in the Internet 111.

Another terminal device can be connected either to the samePacket-Switched Core Network 107A or to another Packet-Switched CoreNetwork 107B; e.g., of another communications network 100B. ThePacket-Switched Core Network 107B is connected to the IMS 109B whichfurther includes IMS Core 203B. The IMS 109A may communicate with theIMS 109B either directly or via the Internet 111.

FIG. 3 shows an exemplary signalling diagram for PoC. The user at theterminal device 101 presses the talk button 167. The terminal device 101sends a request to the PoC server 201 which is in “Floor Idle” state(step 301). The PoC server 201 notifies the other terminal device 101Bby sending a notification J13, grants the floor and notifies theterminal device 101 by sending an acknowledgement J15. Then the terminaldevice 101 signals the user Talk proceed-notification; e.g., by alertingthe user with voice output part 159. The user starts speaking, andspeech received by the voice input part 157 is coded and transmitted inpackets M11, M21, M31, M41, . . . , M51 to the PoC server 201 whichfurther forwards the messages to the other terminal device 101B aspackets M12, M22, M32, M42, . . . , M52.

The user can speak as long as the talk button 167 is pressed. Afterreleasing the talk button 167, the terminal device 101 signals therelease of the talk button to the PoC server 201 by sending a messageJ21. The PoC server 201 notifies the other terminal device 101 bysending a message J23, and then sends an acknowledgement J25 to theterminal device 101. Then, the PoC server 201 returns to the Floor Idlestate, as designated at step 301.

FIGS. 4 and 5 show more detailed signalling diagrams for PoC.

FIG. 4 shows a case where both terminal devices have enabled so-calledearly session and automatic answer.

Dashed box 41 shows how a session is created. When terminal device 101is switched on, it sends an SIP INVITE message to the IMS core 203Awhich further forwards the message to PoC server 201, which respondswith SIP 200 OK that is forwarded by the IMS core 203A to the terminaldevice 101. The terminal device 101 responds with an acknowledgement SIPACK. The other terminal 101B performs similar messaging with the PoCserver 201.

Dashed box 43 shows how a PoC is then used. When the talk button 167 ispressed at a terminal device 101, the terminal device 101 sends messageJ11, which is a SIP REFER message. The IMS core 203A forwards messageJ11 to PoC server which transmits message J13 that is RTCP: Floor takenmessage to the other terminal device 101B. The other terminal device101B indicates that it is now listening to the terminal device 101;e.g., by playing a suitable acoustic signal.

The PoC server 201 responds with message J15 that is RTCP: FloorGranted. Then, the terminal device 101 indicates to the user that he orshe can now talk; e.g., by playing a suitable acoustic signal. The PoCfurthermore sends an SIP 202 message to the terminal device 101.

Speech packets MN1 coded at the terminal device 101 are transmitted asRTP: Talk bursts through the IMS core 203A to the PoC server 201. ThePoC server 201 forwards them as speech packets MN2, transmitting them asRTP: Talk bursts to the other terminal device 101B through the IMS core203B. The other terminal device 101B receives the speech packets MN2,decodes them, and converts them to an audible form so that the user ofthe other terminal device 101B can hear a reproduction of the speechcoded by the terminal device 101.

When talk button 167 is released at the terminal device 101, theterminal device sends message J21 that is RTCP: Floor release message.The PoC server 201 sends message J23 that is RTCP: Floor idle message tothe other terminal device 101B. The other terminal device indicates tothe user that the floor is now idle; i.e., that he or she may press thepush button 167 of his or her terminal device 101B.

The PoC server 201 responds with SIP NOTIFY, and the terminalacknowledges by sending SIP 200 OK message. The PoC server 201 respondsonce more by sending message J25 that is RTCP:

Floor idle message.

FIG. 5 shows late media and manual answer for one-to-one communicationusing PoC. Now responsive to terminal device 101 detecting a pressing oftalk button 167, it sends message J11 that is SIP INVITE to IMS core203A. The IMS core 203A forwards the SIP INVITE to PoC server 201 thatsends message J13 that is SIP invite to IMS core 203B. The IMS core 203Bforwards the SIP INVITE to the other terminal device 101B, and passesSIP 100 Trying message to PoC server which forwards it through the IMScore 203A to the terminal device 101.

Upon receiving SIP INVITE, the other terminal device 101B indicates thata talk is intented, such as by playing a suitable audible signal, andpasses SIP 180 Ringing message through the IMS core 203B, the PoC server201, and the IMS core 203A to the terminal device 101. The terminaldevice 101 alerts the user.

When a user of the other terminal device 101B accepts the talk, such asby pressing a suitable button, the other terminal 101B transmits SIP 200OK message through the IMS core 203B to the PoC server 201 which thensends message J15 which is RTCP: Floor granted message to the terminaldevice 101. The SIP 200 OK is furthermore passed to the terminal device101, after which the terminal device 101 alerts the user. Someacknowledgements and other SIP messages furthermore may be transmitted.The transmission of speech packets in messages MN1 and MN2 neverthelesstakes place in a very similar manner than in the example discussed withreference to FIG. 4.

FIGS. 6A and 6B illustrate possible structures of the message carryinggeographical location information. The message can be J11 (signallingfrom terminal device 101 to the PoC server 201 that a talk button 167has been pressed), M11 (any speech packet or particularly the firstspeech packet from the terminal device 101), J13 (signalling from PoCserver 201 to the other terminal device 101B that a talk button 167 hasbeen pressed at the terminal device 101), or M12 (any speech packet orparticularly the first speech packet from the PoC server 201 to theother terminal device 101B).

The first terminal device 101 finds out its geographical location 65.For doing this, it may use any suitable locationing method. Currently,terminal devices with assisted Global Positioning System A-GPS receiversare under development. A-GPS enables quick & accurate location findingfor the terminal device.

When the user of the first terminal device 101 pushes the talk button167 in order to use the push-to-talk service, the first terminal device101 requests the network for a permission to speak, and finally thepush-to-talk message is generated by coding microphone input. Therequest for a permission to speak (message J11) or any of the speechmessages (MN1, especially M11) may include the geographical locationinformation 65.

As shown in FIG. 6A, the push-to-talk message J11, M11, J13, or M12 mayinclude a flag 63 “location information present” in the header field 61indicating that the geographical location 65 follows. As an alternative,as illustrated in FIG. 6B, the least-significant bits of the speechmessage 64 having coded speech may be used to indicate the geographicallocation 65. The latter possibility enables a proprietary solution.

The other terminal device 101B receives the push-to-talk message. Afterchecking the flag 63 in the header field 61 or the least significantbits 65, an application, such as the PoC application 165, extracts thegeographical location information 65.

The other terminal device 101B knows its own geographical location 65B.

The other terminal device 101B compares its own geographical location65B with the geographical location 65 of the terminal device 101.Information based on a comparison result is shown to the user of theother terminal device 101B. This information may include any of thefollowing: direction of the terminal device 101 (may require use of adigital compass in the other terminal device 101B); distance of theterminal device 101 from the other terminal device 101B; show on a mapthe geographical location 65 of terminal device 101 vs. its owngeographical location 65B; or just displaying the geographical location65 of terminal device 101 vs. its own geographical location 65B.

It is by no means necessary that the geographical location 65 isreceived as such at the other terminal device 101B. The other terminaldevice 101B may transmit, such as by responding to any one of messagesJ13 or MN2 (particularly M12) its own geographical location 65B to anetwork unit; e.g., to the PoC server 201 which then computes thedifference and transmits information based thereon to both the terminaldevice 101 and the other terminal device 101B.

The terminal device 101, for example, in one of its applications, suchas the PoC application 165, may have a settings menu for setting a“push-to-talk” item, under which a user can tick on/off the followingitems:

send own location with push-to-talk; and

show talking party's direction/location.

In other words, the user sending his or her own location has fullcontrol over whether or not the location is to be sent or, as describedabove, the parents or employer, for example, can control thetransmission of the geographical location information.

Although the present invention has been described with reference tospecific embodiments, those of skill in the art will recognize thatchanges may be made thereto without departing from the spirit and scopeof the present invention as set forth in the hereafter appended claims.

1-14. (canceled)
 15. A method for receiving location information, themethod comprising: receiving a message at a first terminal deviceindicating that a user of a second terminal device has pressed a talkbutton, the message including a geographical location of the secondterminal device; and indicating the geographical location of the secondterminal device to a user of the first terminal device.
 16. A method forreceiving location information as claimed 15, wherein the step ofindicating further comprises one of: indicating a direction of the firstterminal device from the geographical location of the second terminaldevice; indicating a distance of the first terminal device from thesecond terminal device; indicating a geographical location of the firstterminal device on a map together with the geographical location of thesecond terminal device; and indicating coordinates of both the firstterminal device and the second terminal device.
 17. A method forreceiving location information as claimed in claim 15, wherein themessage is a Push-to-Talk over Cellular message.
 18. A method forreceiving location information as claimed in claim 17, wherein thePush-to-Talk over Cellular message is one of a REFER message, a Floortaken message and a Talk burst.
 19. A method for transmitting locationinformation, the method comprising: writing information into a message,in response to a user of a first terminal device pressing a talk button,the information describing a geographical location of the first terminaldevice; and transmitting the message to one of a second terminal deviceand a communications network.
 20. A method for transmitting locationinformation as claimed in claim 19, wherein the information describingthe geographical location of the first terminal device is written intothe message only if a parameter controllable by the user of the firstterminal device shows that the geographical location may be indicated.21. A method for transmitting location information as claimed in claim19, wherein the information describing the geographical location of thefirst terminal device is written into the message only if a parametercontrollable by the user of the first terminal device shows that thegeographical location may be indicated to another terminal device towhich the message is to be sent.
 22. A method for transmitting locationinformation as claimed in claim 19, wherein the message is aPush-to-Talk over Cellular message.
 23. A method for transmittinglocation information as claimed in claim 22, wherein the Push-to-Talkover Cellular message is one of a REFER message, a Floor taken messageand a Talk burst.
 24. A terminal device, comprising: parts for receivinga message indicating that a user of a further terminal device haspressed a talk button, the message including a geographical location ofthe further terminal device; and parts for indicating the geographicallocation of the further terminal device to a user of the terminaldevice.
 25. A terminal device as claimed in claim 24, wherein the partsfor indicating the geographical location of the further terminal deviceare designed to one of: indicate a direction of the terminal device fromthe geographical location of the further terminal device; indicate adistance of the terminal device from the further terminal device;indicate a geographical location of the terminal device on a maptogether with a geographical location of the further terminal device;and indicate coordinates of both the terminal device and the furtherterminal device.
 26. A terminal device as claimed in claim 24, whereinthe message is a Push-to-Talk over Cellular message.
 27. A terminaldevice as claimed in claim 26, wherein the Push-to-Talk over Cellularmessage is one of a REFER message, a Floor taken message and a Talkburst.
 28. A terminal device, comprising: parts for writing informationinto a message, responsive to a user of the terminal device pressing atalk button, the information describing a geographical location of theterminal device; and parts for transmitting the message to one of afurther terminal device and a communications network.
 29. A terminaldevice as claimed in claim 28, wherein the information describing thegeographical location of the terminal device is written into the messageonly if a parameter controllable by the user of the terminal deviceshows that the geographical location may be indicated.
 30. A terminaldevice as claimed in claim 28, wherein the information describing thegeographical location of the terminal device is written into the messageonly if a parameter controllable by the user of the terminal deviceshows that the geographical location may be indicated to anotherterminal device to which the message is to be sent.
 31. A terminaldevice as claimed in claim 28, wherein the message is a Push-to-Talkover Cellular message.
 32. A terminal device as claimed in claim 31,wherein the Push-to-Talk over Cellular message is one of a REFERmessage, a Floor taken message and a Talk burst.